Output voltages of electronic cigarettes are often constant (for example, 3.3 volts). When an electronic cigarette is working under a constant voltage output mode, in the condition that the load to which the output voltage is provided remains unchanged, the greater the output voltage of the electronic cigarette, the more heat the coil generates, and the hotter the vapor flow during smoking, thereby bringing a different experience to a user. By comparison, the lower the output voltage of the electronic cigarette, the less the amount of airflow generated during smoking, thus failing to improve the user experience. In addition, the resistance of the coil is not detected under the constant voltage output mode. If the resistance of the coil is low but the output voltage is high, a dry-burn effect will occur in the coil. If the resistance of the coil is high but the output voltage is low, the amount of vapor flow generated during smoking is decreased.